1. Technical Field That Invention Belongs
The present invention relates to a table type display device for displaying an image on a screen of a horizontal located type, particularly, a table type display device with easy exchange of projector and easy change of resolution in display according to user's needs, and an assembling method thereof.
2. Related Technology
As a conventional table type display device to display the image on the screen of the horizontal location type, there are a display device of type of displaying images on an LCD panel constituted by for example burying one LCD panel of about 10 inches-14 inches in a horizontal plane of a table type casing, and a display device of the type shown in FIG. 15. The conventional table type display device shown in FIG. 15 corresponds to the device described in FIG. 3 of Japanese Patent Laid-open No. 305,079/2000, and comprises one projector 51 for projecting luminous flux to form an image, two reflection mirrors 52 and 53 for bending an optical path of luminous flux projected from the projector 51 twice, and a transparent screen 54 of the horizontal location type, from which luminous flux bent two times, is projected to an optical path by these reflection mirrors 52 and 53, which are built in a same casing 55, the casing 55 is constituted in the shape of the desk, and the transparent screen 54 constitutes the desk plane (table plane).
A conventional table type display device shown in FIG. 15 adopts a construction in which the luminous flux projected from one projector 51 is projected on a transparent type screen 54 through two the reflection mirrors 52 and 53, so that the resolution of the projector becomes the same as the display resolution on the screen, and thus for example, in the case that a projector with the resolution of XGA (1024×768 pixels) is used, the display resolution on the screen will be fixed to XGA.
For example, in case of using a projector of rear projection system marketed as the above projector, the projector will break in a short term of about one year though it depends on the using frequency of the display device. On the one hand, since the restyling or model change is frequently performed to the projector of a rear projection system on the market, when about one year passes after activation, the projector of a rear projection system on the market becomes manufacturing discontinuance for restyling, therefore, the case that the projector of the same model cannot be obtained, frequently generates.
The conventional table type display device described in FIG. 15 is assumed to be a structure to build the projector 51 being an constructional element, reflection mirrors 52, 53, and the transparent screen 54, etc. into the same casing 55 as one body, so that for example, when the necessity for exchanging the projector by the failure is caused, if the projector of the same model can not be obtained, it is necessary to use a projector of another model to which the specification is similar as much as possible. In that case, for example, even if a projector to which the resolving degree, the projection distance, and the projection angle are common, is used, there are a lot of cases that the size and the shape etc. of the projector before and after the exchange are different, so that it is necessary to recompose the support structure that supports the projector to the casing, and the exchange of the projector is extremely difficult. Moreover, as described above, it is assumed the structure to build the projector 51, reflection mirrors 52 and 53, and the transparent screen 54, etc. into the same casing 55 as one body, so that by using the projector with a different resolution properly, with a casing, a reflection mirror, and a transparent screen etc. of a design commonly, it is not possible to constitute the table type display device according to the display resolution corresponding to user's needs and user's budgets and modes, and thus freedom degree of the system design becomes lower.